It has long been known to use a filler such as carbon black and, silica for reinforcing rubber. When carbon black is used to reinforce rubber, a tire excellent in abrasion resistance can be produced. Silica, compared with carbon black, has a lower tan δ at a high temperature (around 60° C.), which is an indicator of the rolling resistance and has a high tan δ at a low temperature (around 0° C.), which is an indicator of the grip on wet roads, and therefore, for example, when used as a tire tread rubber composition, a tire having a low rolling resistance and a high grip can be produced (see, for example, Japanese Unexamined Patent Publication (Kokai) No. 10-273559 and Japanese Unexamined Patent Publication (Kokai) No. 6-248116).